As is known, handheld printers afford mobile convenience to users. Users determine the navigation path of a given swath of printing. In some instances, this includes random movement over a media. In others, it includes back-and-forth movement attempting to simulate a stationary printer. Regardless, printer speed, printer orientation, and the path of motion over the media, to name a few, are irregular and virtually random. To assist with this, optical and/or mechanical sensors are known to sense position on the paper and activate printing whenever the area underneath the printing element matches an imprinted section of a to-be-printed latent image.
With reference to FIG. 6, it has been suggested that an optical sensor 1, 2, be placed both in front and behind a printhead 3. Considering that the optical position sensors are likely to lose positioning if they cross a boundary 4 of the paper 5, the illustrated configuration results in a very large unprintable area, such as in the gap G1 beneath the printhead between a bottommost fluid firing actuator in a column of actuators 6 and the bottom sensor 2. While a smaller printhead would reduce the gap, it would correspondingly reduce an amount of ink in the printhead. Similarly, a smaller but significant gap G2 results at the top between an uppermost fluid firing actuator of the column 6 and the top sensor 1. While the gaps adversely impact design, one advantage does exist in that the sensors 1, 2 are aligned vertically with the column 6, e.g., line V-V, and unprintable edge margins to the sides of the column 6 are limited only by the ability of the operator to complete a swath of printing without overrunning the paper boundary 4.
Nonetheless, a need exists in the art of handheld printers to optimize placement of the printhead and sensors so that the printable area is maximized, while the paper gap is minimized during printing. In that prior handheld printers have had ongoing problems keeping their printhead and/or sensors consistently spaced from the paper, the need must also contemplate maintaining an optimal spacing from the paper. Naturally, any improvements along such lines should further contemplate good engineering practices, such as relative inexpensiveness, stability, flexibility, ease of manufacturing, etc.